Commercially available, computerized fabric cutting machines include a frame in which an endless loop of bristle blocks (bristles) is mounted. The conveyor-type loop of bristles is trained around driving and support mechanisms such as rollers or toothed wheels. The loop of bristles is rotated and pulls fabric from either a roll of fabric or spreading table mounted on or near the frame. The fabric is moved from the roll or spreading table to a desired location where a cutting head having a knife is positioned.
The cutting head is mounted on a carriage which is coupled to the frame. The carriage, the cutting head, or both are motorized so that the cutting head may move in an X-Y plane. Motion of the cutting head is controlled by a computer or other programmable device so that desired patterns may be cut from the fabric. Once the desired patterns are cut, the loop of bristles is rotated again, the cut pieces of fabric are removed, and the remaining fabric is carried away from the cutting head to a conveyor take-off table.
The bristle bed provides a fabric supporting surface and can withstand repeated penetration by the knife in the cutting head without being damaged. The bristle bed also permits suction from a vacuum to be applied to the fabric to hold it firmly in place while being cut. During the cutting process, the knife in the cutting head cuts through the fabric and dips down between the bristles in order to cut-out individual pieces of fabric. In so doing, loose fibers, threads, small pieces of work material, and other fabric debris collects in the spaces between the bristles. When vacuum grip is used, such debris is pulled down toward the base of the bristles and is firmly lodged in-between them. If left unremoved, this debris hinders the efficient operation of the vacuum, interferes with the knife of the cutting head, and causes premature wear. Thus, in order to maintain vacuum and cutting efficiency the bristle blocks which make up the bed must be periodically cleaned.
The primary method for cleaning such bristles is through a giant vacuum such as that marketed under the trademark SwarfEater and manufactured by Phoenix Engineering Incorporated. The use of this machine necessitates shutting down the fabric cutting machine and manually operating the vacuum to clean the bristle blocks.
Other mechanisms used to clean bristles include the one shown in U.S. Pat. No. 4,224,711. The device shown in this patent includes a mechanism which, in general terms, shakes the bristles clean. A problem with this type of cleaner is that the bristle blocks must be separated from the cutting machine, cleaned, and then reassembled onto the machine after cleaning. This process is highly labor intensive and, therefore, costly.
Another device used to clean bristles is shown in U.S. Pat. No. 5,412,836. This device has a cleaning head which is driven across the bristle block loop and uses vacuum and combing action to clean the bristles. A problem with this device is that it is mechanically complex. Among other assemblies, it requires a vacuum source for the cleaning head and a driving mechanism and guide to move the cleaning head across the bristle blocks. Moreover, the device takes a relatively long time to clean the bristles, as it can clean only a relatively small portion of the loop of bristle blocks at a time. One problem common to all of the described cleaning devices is that the cutting machines with which they are used must be shut down (or taken off line) to accomplish the cleaning.
Accordingly, it would be desirable to have a bristle cleaning device that overcomes the problems associated with presently available devices. More specifically, it would be desirable if the bristle cleaning device could clean the bristles while the cloth cutter was still operating and clean bristle beds that are already dirtied and, therefore, not run continuously.